Electromechanical actuator for controlling the movement of a moving outer part of an aircraft, and aircraft including one such electromechanical actuator

Abstract

An electromechanical actuator includes an actuator that is translatable along an axis relative to a case and that is made up of a deployed part and a non-deployed part, which are following one another along the axis and which are respectively deployed and not deployed outside the case. The axial span of the deployed part varies proportionally opposite that of the non-deployed part as a function of the translated position of the actuator. The actuator also includes an electric motor for translating the actuator, which is supported by the case and is connected to the non-deployed part of the actuator by a transmission. The case defines an inner volume inside which the non-deployed part of the actuator, the motor and the transmission are arranged. The inner volume is, during operation of the actuator, pressurized while being filled with a gaseous medium.

What is claimed is: 
     
       1. An electromechanical actuator for controlling the movement of a moving outer part of an aircraft, the electromechanical actuator comprising:
 a case, 
 an actuating member, that is translatable along an axis relative to the case and that is made up of a deployed part and a non-deployed part, which are following one another along the axis and which are respectively deployed and not deployed outside the case, the axial span of the deployed part varying proportionally opposite that of the non-deployed part as a function of the translated position of the actuating member relative to the case, 
 an electric motor for translating the actuating member, which is supported by the case and is connected to the non-deployed part of the actuating member by a transmission mechanism, the case defining an inner volume inside which the non-deployed part of the actuating member, the motor and the transmission mechanism are arranged, and 
 sealing elements that seal the inner volume relative to the outside of the case, wherein the inner volume is pressurized by being filled with a gaseous medium so that in use, irrespective of the translated position of the actuating member, the gaseous medium has a pressure greater than or equal to a preset absolute value of at least 1.5 bars, the sealing elements being provided to keep the inner volume pressurized. 
 
     
     
       2. The electromechanical actuator according to  claim 1 , wherein the preset absolute value is at least 2 bars. 
     
     
       3. The electromechanical actuator according to  claim 1 , wherein the preset absolute value is at least 3 bars. 
     
     
       4. The electromechanical actuator according to  claim 1 , wherein the gaseous medium is made up of a neutral gas or a mixture of neutral gases. 
     
     
       5. The electromechanical actuator according to  claim 1 , wherein the sealing elements comprise at least one sealing gasket, which is inserted between the case and the actuating member, while being designed to be pressed against them under the effect of the pressure from the gaseous medium. 
     
     
       6. The electromechanical actuator according to  claim 1 , wherein the transmission mechanism is lubricated exclusively with oil. 
     
     
       7. The electromechanical actuator according to  claim 1 , wherein the actuator further comprises a gas supply device, suitable for recharging the gaseous medium when the pressure of the gaseous medium drops below the preset absolute value. 
     
     
       8. The electromechanical actuator according to  claim 7 , wherein the gas supply device comprises a pressurized gas source, which has a pressure strictly greater than the preset absolute value and that is connected to the inner volume of the case via a pressure regulator of the device that selectively opens or closes the passage between the gas source and the inner volume depending on whether the pressure of the gaseous medium is below the preset absolute value. 
     
     
       9. The electromechanical actuator according to  claim 8 , wherein the gas source is a cartridge supported by the case. 
     
     
       10. The electromechanical actuator according to  claim 7 , wherein the actuator further comprises overpressure release regulator, suitable for discharging part of the gaseous medium outside the case when the pressure of said gaseous medium passes above a predetermined threshold. 
     
     
       11. An aircraft, including:
 a chassis, 
 an outer part, which is movable relative to the chassis, and 
 an electromechanical actuator for controlling the movement of the outer part, this electromechanical actuator being according to  claim 1 , the case of the electromechanical actuator being secured to the chassis while an actuating member of the electromechanical actuator is secured to the outer part. 
 
     
     
       12. The aircraft according to  claim 11 , wherein the outer part is a landing gear.